v1.30.0

• Update buf generate so it populates the recently-added source_file_descriptors field of the CodeGeneratorRequest message. This provides the plugin with access to options that are configured to only be retained in source and not at runtime (via field option). Descriptors in the proto_file field will not include any options configured this way for the files named in file_to_generate field.
• Add --exclude-source-retention-options flag to buf build, which causes options configured to only be retained in source to be stripped from the output descriptors.